jacket

English "jacket" comes from Middle French jacquet, a diminutive form of Old French jaque, itself built with the Old French diminutive suffix -et.

The word passed from Old French jaque into Middle French jacquet, gaining that little "-et" ending along the way before English borrowed it as "jacket."

The diminutive suffix -et in jacquet traces back through Late Latin -ittus toward Proto-Italic and Proto-Indo-European roots, though no other specific English cognate is given in the record.